Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2333 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
new file mode 100644
index 000000000..c21acebe8
--- /dev/null
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -0,0 +1,2333 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Target based USB-Gadget
+ *
+ * UAS protocol handling, target callbacks, configfs handling,
+ * BBB (USB Mass Storage Class Bulk-Only (BBB) and Transport protocol handling.
+ *
+ * Author: Sebastian Andrzej Siewior <bigeasy at linutronix dot de>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/configfs.h>
+#include <linux/ctype.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/composite.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/storage.h>
+#include <scsi/scsi_tcq.h>
+#include <target/target_core_base.h>
+#include <target/target_core_fabric.h>
+#include <asm/unaligned.h>
+
+#include "tcm.h"
+#include "u_tcm.h"
+#include "configfs.h"
+
+#define TPG_INSTANCES		1
+
+struct tpg_instance {
+	struct usb_function_instance	*func_inst;
+	struct usbg_tpg			*tpg;
+};
+
+static struct tpg_instance tpg_instances[TPG_INSTANCES];
+
+static DEFINE_MUTEX(tpg_instances_lock);
+
+static inline struct f_uas *to_f_uas(struct usb_function *f)
+{
+	return container_of(f, struct f_uas, function);
+}
+
+/* Start bot.c code */
+
+static int bot_enqueue_cmd_cbw(struct f_uas *fu)
+{
+	int ret;
+
+	if (fu->flags & USBG_BOT_CMD_PEND)
+		return 0;
+
+	ret = usb_ep_queue(fu->ep_out, fu->cmd.req, GFP_ATOMIC);
+	if (!ret)
+		fu->flags |= USBG_BOT_CMD_PEND;
+	return ret;
+}
+
+static void bot_status_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct usbg_cmd *cmd = req->context;
+	struct f_uas *fu = cmd->fu;
+
+	transport_generic_free_cmd(&cmd->se_cmd, 0);
+	if (req->status < 0) {
+		pr_err("ERR %s(%d)\n", __func__, __LINE__);
+		return;
+	}
+
+	/* CSW completed, wait for next CBW */
+	bot_enqueue_cmd_cbw(fu);
+}
+
+static void bot_enqueue_sense_code(struct f_uas *fu, struct usbg_cmd *cmd)
+{
+	struct bulk_cs_wrap *csw = &fu->bot_status.csw;
+	int ret;
+	unsigned int csw_stat;
+
+	csw_stat = cmd->csw_code;
+	csw->Tag = cmd->bot_tag;
+	csw->Status = csw_stat;
+	fu->bot_status.req->context = cmd;
+	ret = usb_ep_queue(fu->ep_in, fu->bot_status.req, GFP_ATOMIC);
+	if (ret)
+		pr_err("%s(%d) ERR: %d\n", __func__, __LINE__, ret);
+}
+
+static void bot_err_compl(struct usb_ep *ep, struct usb_request *req)
+{
+	struct usbg_cmd *cmd = req->context;
+	struct f_uas *fu = cmd->fu;
+
+	if (req->status < 0)
+		pr_err("ERR %s(%d)\n", __func__, __LINE__);
+
+	if (cmd->data_len) {
+		if (cmd->data_len > ep->maxpacket) {
+			req->length = ep->maxpacket;
+			cmd->data_len -= ep->maxpacket;
+		} else {
+			req->length = cmd->data_len;
+			cmd->data_len = 0;
+		}
+
+		usb_ep_queue(ep, req, GFP_ATOMIC);
+		return;
+	}
+	bot_enqueue_sense_code(fu, cmd);
+}
+
+static void bot_send_bad_status(struct usbg_cmd *cmd)
+{
+	struct f_uas *fu = cmd->fu;
+	struct bulk_cs_wrap *csw = &fu->bot_status.csw;
+	struct usb_request *req;
+	struct usb_ep *ep;
+
+	csw->Residue = cpu_to_le32(cmd->data_len);
+
+	if (cmd->data_len) {
+		if (cmd->is_read) {
+			ep = fu->ep_in;
+			req = fu->bot_req_in;
+		} else {
+			ep = fu->ep_out;
+			req = fu->bot_req_out;
+		}
+
+		if (cmd->data_len > fu->ep_in->maxpacket) {
+			req->length = ep->maxpacket;
+			cmd->data_len -= ep->maxpacket;
+		} else {
+			req->length = cmd->data_len;
+			cmd->data_len = 0;
+		}
+		req->complete = bot_err_compl;
+		req->context = cmd;
+		req->buf = fu->cmd.buf;
+		usb_ep_queue(ep, req, GFP_KERNEL);
+	} else {
+		bot_enqueue_sense_code(fu, cmd);
+	}
+}
+
+static int bot_send_status(struct usbg_cmd *cmd, bool moved_data)
+{
+	struct f_uas *fu = cmd->fu;
+	struct bulk_cs_wrap *csw = &fu->bot_status.csw;
+	int ret;
+
+	if (cmd->se_cmd.scsi_status == SAM_STAT_GOOD) {
+		if (!moved_data && cmd->data_len) {
+			/*
+			 * the host wants to move data, we don't. Fill / empty
+			 * the pipe and then send the csw with reside set.
+			 */
+			cmd->csw_code = US_BULK_STAT_OK;
+			bot_send_bad_status(cmd);
+			return 0;
+		}
+
+		csw->Tag = cmd->bot_tag;
+		csw->Residue = cpu_to_le32(0);
+		csw->Status = US_BULK_STAT_OK;
+		fu->bot_status.req->context = cmd;
+
+		ret = usb_ep_queue(fu->ep_in, fu->bot_status.req, GFP_KERNEL);
+		if (ret)
+			pr_err("%s(%d) ERR: %d\n", __func__, __LINE__, ret);
+	} else {
+		cmd->csw_code = US_BULK_STAT_FAIL;
+		bot_send_bad_status(cmd);
+	}
+	return 0;
+}
+
+/*
+ * Called after command (no data transfer) or after the write (to device)
+ * operation is completed
+ */
+static int bot_send_status_response(struct usbg_cmd *cmd)
+{
+	bool moved_data = false;
+
+	if (!cmd->is_read)
+		moved_data = true;
+	return bot_send_status(cmd, moved_data);
+}
+
+/* Read request completed, now we have to send the CSW */
+static void bot_read_compl(struct usb_ep *ep, struct usb_request *req)
+{
+	struct usbg_cmd *cmd = req->context;
+
+	if (req->status < 0)
+		pr_err("ERR %s(%d)\n", __func__, __LINE__);
+
+	bot_send_status(cmd, true);
+}
+
+static int bot_send_read_response(struct usbg_cmd *cmd)
+{
+	struct f_uas *fu = cmd->fu;
+	struct se_cmd *se_cmd = &cmd->se_cmd;
+	struct usb_gadget *gadget = fuas_to_gadget(fu);
+	int ret;
+
+	if (!cmd->data_len) {
+		cmd->csw_code = US_BULK_STAT_PHASE;
+		bot_send_bad_status(cmd);
+		return 0;
+	}
+
+	if (!gadget->sg_supported) {
+		cmd->data_buf = kmalloc(se_cmd->data_length, GFP_ATOMIC);
+		if (!cmd->data_buf)
+			return -ENOMEM;
+
+		sg_copy_to_buffer(se_cmd->t_data_sg,
+				se_cmd->t_data_nents,
+				cmd->data_buf,
+				se_cmd->data_length);
+
+		fu->bot_req_in->buf = cmd->data_buf;
+	} else {
+		fu->bot_req_in->buf = NULL;
+		fu->bot_req_in->num_sgs = se_cmd->t_data_nents;
+		fu->bot_req_in->sg = se_cmd->t_data_sg;
+	}
+
+	fu->bot_req_in->complete = bot_read_compl;
+	fu->bot_req_in->length = se_cmd->data_length;
+	fu->bot_req_in->context = cmd;
+	ret = usb_ep_queue(fu->ep_in, fu->bot_req_in, GFP_ATOMIC);
+	if (ret)
+		pr_err("%s(%d)\n", __func__, __LINE__);
+	return 0;
+}
+
+static void usbg_data_write_cmpl(struct usb_ep *, struct usb_request *);
+static int usbg_prepare_w_request(struct usbg_cmd *, struct usb_request *);
+
+static int bot_send_write_request(struct usbg_cmd *cmd)
+{
+	struct f_uas *fu = cmd->fu;
+	struct se_cmd *se_cmd = &cmd->se_cmd;
+	struct usb_gadget *gadget = fuas_to_gadget(fu);
+	int ret;
+
+	init_completion(&cmd->write_complete);
+	cmd->fu = fu;
+
+	if (!cmd->data_len) {
+		cmd->csw_code = US_BULK_STAT_PHASE;
+		return -EINVAL;
+	}
+
+	if (!gadget->sg_supported) {
+		cmd->data_buf = kmalloc(se_cmd->data_length, GFP_KERNEL);
+		if (!cmd->data_buf)
+			return -ENOMEM;
+
+		fu->bot_req_out->buf = cmd->data_buf;
+	} else {
+		fu->bot_req_out->buf = NULL;
+		fu->bot_req_out->num_sgs = se_cmd->t_data_nents;
+		fu->bot_req_out->sg = se_cmd->t_data_sg;
+	}
+
+	fu->bot_req_out->complete = usbg_data_write_cmpl;
+	fu->bot_req_out->length = se_cmd->data_length;
+	fu->bot_req_out->context = cmd;
+
+	ret = usbg_prepare_w_request(cmd, fu->bot_req_out);
+	if (ret)
+		goto cleanup;
+	ret = usb_ep_queue(fu->ep_out, fu->bot_req_out, GFP_KERNEL);
+	if (ret)
+		pr_err("%s(%d)\n", __func__, __LINE__);
+
+	wait_for_completion(&cmd->write_complete);
+	target_execute_cmd(se_cmd);
+cleanup:
+	return ret;
+}
+
+static int bot_submit_command(struct f_uas *, void *, unsigned int);
+
+static void bot_cmd_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_uas *fu = req->context;
+	int ret;
+
+	fu->flags &= ~USBG_BOT_CMD_PEND;
+
+	if (req->status < 0)
+		return;
+
+	ret = bot_submit_command(fu, req->buf, req->actual);
+	if (ret)
+		pr_err("%s(%d): %d\n", __func__, __LINE__, ret);
+}
+
+static int bot_prepare_reqs(struct f_uas *fu)
+{
+	int ret;
+
+	fu->bot_req_in = usb_ep_alloc_request(fu->ep_in, GFP_KERNEL);
+	if (!fu->bot_req_in)
+		goto err;
+
+	fu->bot_req_out = usb_ep_alloc_request(fu->ep_out, GFP_KERNEL);
+	if (!fu->bot_req_out)
+		goto err_out;
+
+	fu->cmd.req = usb_ep_alloc_request(fu->ep_out, GFP_KERNEL);
+	if (!fu->cmd.req)
+		goto err_cmd;
+
+	fu->bot_status.req = usb_ep_alloc_request(fu->ep_in, GFP_KERNEL);
+	if (!fu->bot_status.req)
+		goto err_sts;
+
+	fu->bot_status.req->buf = &fu->bot_status.csw;
+	fu->bot_status.req->length = US_BULK_CS_WRAP_LEN;
+	fu->bot_status.req->complete = bot_status_complete;
+	fu->bot_status.csw.Signature = cpu_to_le32(US_BULK_CS_SIGN);
+
+	fu->cmd.buf = kmalloc(fu->ep_out->maxpacket, GFP_KERNEL);
+	if (!fu->cmd.buf)
+		goto err_buf;
+
+	fu->cmd.req->complete = bot_cmd_complete;
+	fu->cmd.req->buf = fu->cmd.buf;
+	fu->cmd.req->length = fu->ep_out->maxpacket;
+	fu->cmd.req->context = fu;
+
+	ret = bot_enqueue_cmd_cbw(fu);
+	if (ret)
+		goto err_queue;
+	return 0;
+err_queue:
+	kfree(fu->cmd.buf);
+	fu->cmd.buf = NULL;
+err_buf:
+	usb_ep_free_request(fu->ep_in, fu->bot_status.req);
+err_sts:
+	usb_ep_free_request(fu->ep_out, fu->cmd.req);
+	fu->cmd.req = NULL;
+err_cmd:
+	usb_ep_free_request(fu->ep_out, fu->bot_req_out);
+	fu->bot_req_out = NULL;
+err_out:
+	usb_ep_free_request(fu->ep_in, fu->bot_req_in);
+	fu->bot_req_in = NULL;
+err:
+	pr_err("BOT: endpoint setup failed\n");
+	return -ENOMEM;
+}
+
+static void bot_cleanup_old_alt(struct f_uas *fu)
+{
+	if (!(fu->flags & USBG_ENABLED))
+		return;
+
+	usb_ep_disable(fu->ep_in);
+	usb_ep_disable(fu->ep_out);
+
+	if (!fu->bot_req_in)
+		return;
+
+	usb_ep_free_request(fu->ep_in, fu->bot_req_in);
+	usb_ep_free_request(fu->ep_out, fu->bot_req_out);
+	usb_ep_free_request(fu->ep_out, fu->cmd.req);
+	usb_ep_free_request(fu->ep_in, fu->bot_status.req);
+
+	kfree(fu->cmd.buf);
+
+	fu->bot_req_in = NULL;
+	fu->bot_req_out = NULL;
+	fu->cmd.req = NULL;
+	fu->bot_status.req = NULL;
+	fu->cmd.buf = NULL;
+}
+
+static void bot_set_alt(struct f_uas *fu)
+{
+	struct usb_function *f = &fu->function;
+	struct usb_gadget *gadget = f->config->cdev->gadget;
+	int ret;
+
+	fu->flags = USBG_IS_BOT;
+
+	config_ep_by_speed_and_alt(gadget, f, fu->ep_in, USB_G_ALT_INT_BBB);
+	ret = usb_ep_enable(fu->ep_in);
+	if (ret)
+		goto err_b_in;
+
+	config_ep_by_speed_and_alt(gadget, f, fu->ep_out, USB_G_ALT_INT_BBB);
+	ret = usb_ep_enable(fu->ep_out);
+	if (ret)
+		goto err_b_out;
+
+	ret = bot_prepare_reqs(fu);
+	if (ret)
+		goto err_wq;
+	fu->flags |= USBG_ENABLED;
+	pr_info("Using the BOT protocol\n");
+	return;
+err_wq:
+	usb_ep_disable(fu->ep_out);
+err_b_out:
+	usb_ep_disable(fu->ep_in);
+err_b_in:
+	fu->flags = USBG_IS_BOT;
+}
+
+static int usbg_bot_setup(struct usb_function *f,
+		const struct usb_ctrlrequest *ctrl)
+{
+	struct f_uas *fu = to_f_uas(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+	u16 w_value = le16_to_cpu(ctrl->wValue);
+	u16 w_length = le16_to_cpu(ctrl->wLength);
+	int luns;
+	u8 *ret_lun;
+
+	switch (ctrl->bRequest) {
+	case US_BULK_GET_MAX_LUN:
+		if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_CLASS |
+					USB_RECIP_INTERFACE))
+			return -ENOTSUPP;
+
+		if (w_length < 1)
+			return -EINVAL;
+		if (w_value != 0)
+			return -EINVAL;
+		luns = atomic_read(&fu->tpg->tpg_port_count);
+		if (!luns) {
+			pr_err("No LUNs configured?\n");
+			return -EINVAL;
+		}
+		/*
+		 * If 4 LUNs are present we return 3 i.e. LUN 0..3 can be
+		 * accessed. The upper limit is 0xf
+		 */
+		luns--;
+		if (luns > 0xf) {
+			pr_info_once("Limiting the number of luns to 16\n");
+			luns = 0xf;
+		}
+		ret_lun = cdev->req->buf;
+		*ret_lun = luns;
+		cdev->req->length = 1;
+		return usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC);
+
+	case US_BULK_RESET_REQUEST:
+		/* XXX maybe we should remove previous requests for IN + OUT */
+		bot_enqueue_cmd_cbw(fu);
+		return 0;
+	}
+	return -ENOTSUPP;
+}
+
+/* Start uas.c code */
+
+static void uasp_cleanup_one_stream(struct f_uas *fu, struct uas_stream *stream)
+{
+	/* We have either all three allocated or none */
+	if (!stream->req_in)
+		return;
+
+	usb_ep_free_request(fu->ep_in, stream->req_in);
+	usb_ep_free_request(fu->ep_out, stream->req_out);
+	usb_ep_free_request(fu->ep_status, stream->req_status);
+
+	stream->req_in = NULL;
+	stream->req_out = NULL;
+	stream->req_status = NULL;
+}
+
+static void uasp_free_cmdreq(struct f_uas *fu)
+{
+	usb_ep_free_request(fu->ep_cmd, fu->cmd.req);
+	kfree(fu->cmd.buf);
+	fu->cmd.req = NULL;
+	fu->cmd.buf = NULL;
+}
+
+static void uasp_cleanup_old_alt(struct f_uas *fu)
+{
+	int i;
+
+	if (!(fu->flags & USBG_ENABLED))
+		return;
+
+	usb_ep_disable(fu->ep_in);
+	usb_ep_disable(fu->ep_out);
+	usb_ep_disable(fu->ep_status);
+	usb_ep_disable(fu->ep_cmd);
+
+	for (i = 0; i < UASP_SS_EP_COMP_NUM_STREAMS; i++)
+		uasp_cleanup_one_stream(fu, &fu->stream[i]);
+	uasp_free_cmdreq(fu);
+}
+
+static void uasp_status_data_cmpl(struct usb_ep *ep, struct usb_request *req);
+
+static int uasp_prepare_r_request(struct usbg_cmd *cmd)
+{
+	struct se_cmd *se_cmd = &cmd->se_cmd;
+	struct f_uas *fu = cmd->fu;
+	struct usb_gadget *gadget = fuas_to_gadget(fu);
+	struct uas_stream *stream = cmd->stream;
+
+	if (!gadget->sg_supported) {
+		cmd->data_buf = kmalloc(se_cmd->data_length, GFP_ATOMIC);
+		if (!cmd->data_buf)
+			return -ENOMEM;
+
+		sg_copy_to_buffer(se_cmd->t_data_sg,
+				se_cmd->t_data_nents,
+				cmd->data_buf,
+				se_cmd->data_length);
+
+		stream->req_in->buf = cmd->data_buf;
+	} else {
+		stream->req_in->buf = NULL;
+		stream->req_in->num_sgs = se_cmd->t_data_nents;
+		stream->req_in->sg = se_cmd->t_data_sg;
+	}
+
+	stream->req_in->is_last = 1;
+	stream->req_in->complete = uasp_status_data_cmpl;
+	stream->req_in->length = se_cmd->data_length;
+	stream->req_in->context = cmd;
+
+	cmd->state = UASP_SEND_STATUS;
+	return 0;
+}
+
+static void uasp_prepare_status(struct usbg_cmd *cmd)
+{
+	struct se_cmd *se_cmd = &cmd->se_cmd;
+	struct sense_iu *iu = &cmd->sense_iu;
+	struct uas_stream *stream = cmd->stream;
+
+	cmd->state = UASP_QUEUE_COMMAND;
+	iu->iu_id = IU_ID_STATUS;
+	iu->tag = cpu_to_be16(cmd->tag);
+
+	/*
+	 * iu->status_qual = cpu_to_be16(STATUS QUALIFIER SAM-4. Where R U?);
+	 */
+	iu->len = cpu_to_be16(se_cmd->scsi_sense_length);
+	iu->status = se_cmd->scsi_status;
+	stream->req_status->is_last = 1;
+	stream->req_status->context = cmd;
+	stream->req_status->length = se_cmd->scsi_sense_length + 16;
+	stream->req_status->buf = iu;
+	stream->req_status->complete = uasp_status_data_cmpl;
+}
+
+static void uasp_status_data_cmpl(struct usb_ep *ep, struct usb_request *req)
+{
+	struct usbg_cmd *cmd = req->context;
+	struct uas_stream *stream = cmd->stream;
+	struct f_uas *fu = cmd->fu;
+	int ret;
+
+	if (req->status < 0)
+		goto cleanup;
+
+	switch (cmd->state) {
+	case UASP_SEND_DATA:
+		ret = uasp_prepare_r_request(cmd);
+		if (ret)
+			goto cleanup;
+		ret = usb_ep_queue(fu->ep_in, stream->req_in, GFP_ATOMIC);
+		if (ret)
+			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
+		break;
+
+	case UASP_RECEIVE_DATA:
+		ret = usbg_prepare_w_request(cmd, stream->req_out);
+		if (ret)
+			goto cleanup;
+		ret = usb_ep_queue(fu->ep_out, stream->req_out, GFP_ATOMIC);
+		if (ret)
+			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
+		break;
+
+	case UASP_SEND_STATUS:
+		uasp_prepare_status(cmd);
+		ret = usb_ep_queue(fu->ep_status, stream->req_status,
+				GFP_ATOMIC);
+		if (ret)
+			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
+		break;
+
+	case UASP_QUEUE_COMMAND:
+		transport_generic_free_cmd(&cmd->se_cmd, 0);
+		usb_ep_queue(fu->ep_cmd, fu->cmd.req, GFP_ATOMIC);
+		break;
+
+	default:
+		BUG();
+	}
+	return;
+
+cleanup:
+	transport_generic_free_cmd(&cmd->se_cmd, 0);
+}
+
+static int uasp_send_status_response(struct usbg_cmd *cmd)
+{
+	struct f_uas *fu = cmd->fu;
+	struct uas_stream *stream = cmd->stream;
+	struct sense_iu *iu = &cmd->sense_iu;
+
+	iu->tag = cpu_to_be16(cmd->tag);
+	stream->req_status->complete = uasp_status_data_cmpl;
+	stream->req_status->context = cmd;
+	cmd->fu = fu;
+	uasp_prepare_status(cmd);
+	return usb_ep_queue(fu->ep_status, stream->req_status, GFP_ATOMIC);
+}
+
+static int uasp_send_read_response(struct usbg_cmd *cmd)
+{
+	struct f_uas *fu = cmd->fu;
+	struct uas_stream *stream = cmd->stream;
+	struct sense_iu *iu = &cmd->sense_iu;
+	int ret;
+
+	cmd->fu = fu;
+
+	iu->tag = cpu_to_be16(cmd->tag);
+	if (fu->flags & USBG_USE_STREAMS) {
+
+		ret = uasp_prepare_r_request(cmd);
+		if (ret)
+			goto out;
+		ret = usb_ep_queue(fu->ep_in, stream->req_in, GFP_ATOMIC);
+		if (ret) {
+			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
+			kfree(cmd->data_buf);
+			cmd->data_buf = NULL;
+		}
+
+	} else {
+
+		iu->iu_id = IU_ID_READ_READY;
+		iu->tag = cpu_to_be16(cmd->tag);
+
+		stream->req_status->complete = uasp_status_data_cmpl;
+		stream->req_status->context = cmd;
+
+		cmd->state = UASP_SEND_DATA;
+		stream->req_status->buf = iu;
+		stream->req_status->length = sizeof(struct iu);
+
+		ret = usb_ep_queue(fu->ep_status, stream->req_status,
+				GFP_ATOMIC);
+		if (ret)
+			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
+	}
+out:
+	return ret;
+}
+
+static int uasp_send_write_request(struct usbg_cmd *cmd)
+{
+	struct f_uas *fu = cmd->fu;
+	struct se_cmd *se_cmd = &cmd->se_cmd;
+	struct uas_stream *stream = cmd->stream;
+	struct sense_iu *iu = &cmd->sense_iu;
+	int ret;
+
+	init_completion(&cmd->write_complete);
+	cmd->fu = fu;
+
+	iu->tag = cpu_to_be16(cmd->tag);
+
+	if (fu->flags & USBG_USE_STREAMS) {
+
+		ret = usbg_prepare_w_request(cmd, stream->req_out);
+		if (ret)
+			goto cleanup;
+		ret = usb_ep_queue(fu->ep_out, stream->req_out, GFP_ATOMIC);
+		if (ret)
+			pr_err("%s(%d)\n", __func__, __LINE__);
+
+	} else {
+
+		iu->iu_id = IU_ID_WRITE_READY;
+		iu->tag = cpu_to_be16(cmd->tag);
+
+		stream->req_status->complete = uasp_status_data_cmpl;
+		stream->req_status->context = cmd;
+
+		cmd->state = UASP_RECEIVE_DATA;
+		stream->req_status->buf = iu;
+		stream->req_status->length = sizeof(struct iu);
+
+		ret = usb_ep_queue(fu->ep_status, stream->req_status,
+				GFP_ATOMIC);
+		if (ret)
+			pr_err("%s(%d)\n", __func__, __LINE__);
+	}
+
+	wait_for_completion(&cmd->write_complete);
+	target_execute_cmd(se_cmd);
+cleanup:
+	return ret;
+}
+
+static int usbg_submit_command(struct f_uas *, void *, unsigned int);
+
+static void uasp_cmd_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_uas *fu = req->context;
+	int ret;
+
+	if (req->status < 0)
+		return;
+
+	ret = usbg_submit_command(fu, req->buf, req->actual);
+	/*
+	 * Once we tune for performance enqueue the command req here again so
+	 * we can receive a second command while we processing this one. Pay
+	 * attention to properly sync STAUS endpoint with DATA IN + OUT so you
+	 * don't break HS.
+	 */
+	if (!ret)
+		return;
+	usb_ep_queue(fu->ep_cmd, fu->cmd.req, GFP_ATOMIC);
+}
+
+static int uasp_alloc_stream_res(struct f_uas *fu, struct uas_stream *stream)
+{
+	stream->req_in = usb_ep_alloc_request(fu->ep_in, GFP_KERNEL);
+	if (!stream->req_in)
+		goto out;
+
+	stream->req_out = usb_ep_alloc_request(fu->ep_out, GFP_KERNEL);
+	if (!stream->req_out)
+		goto err_out;
+
+	stream->req_status = usb_ep_alloc_request(fu->ep_status, GFP_KERNEL);
+	if (!stream->req_status)
+		goto err_sts;
+
+	return 0;
+
+err_sts:
+	usb_ep_free_request(fu->ep_out, stream->req_out);
+	stream->req_out = NULL;
+err_out:
+	usb_ep_free_request(fu->ep_in, stream->req_in);
+	stream->req_in = NULL;
+out:
+	return -ENOMEM;
+}
+
+static int uasp_alloc_cmd(struct f_uas *fu)
+{
+	fu->cmd.req = usb_ep_alloc_request(fu->ep_cmd, GFP_KERNEL);
+	if (!fu->cmd.req)
+		goto err;
+
+	fu->cmd.buf = kmalloc(fu->ep_cmd->maxpacket, GFP_KERNEL);
+	if (!fu->cmd.buf)
+		goto err_buf;
+
+	fu->cmd.req->complete = uasp_cmd_complete;
+	fu->cmd.req->buf = fu->cmd.buf;
+	fu->cmd.req->length = fu->ep_cmd->maxpacket;
+	fu->cmd.req->context = fu;
+	return 0;
+
+err_buf:
+	usb_ep_free_request(fu->ep_cmd, fu->cmd.req);
+err:
+	return -ENOMEM;
+}
+
+static void uasp_setup_stream_res(struct f_uas *fu, int max_streams)
+{
+	int i;
+
+	for (i = 0; i < max_streams; i++) {
+		struct uas_stream *s = &fu->stream[i];
+
+		s->req_in->stream_id = i + 1;
+		s->req_out->stream_id = i + 1;
+		s->req_status->stream_id = i + 1;
+	}
+}
+
+static int uasp_prepare_reqs(struct f_uas *fu)
+{
+	int ret;
+	int i;
+	int max_streams;
+
+	if (fu->flags & USBG_USE_STREAMS)
+		max_streams = UASP_SS_EP_COMP_NUM_STREAMS;
+	else
+		max_streams = 1;
+
+	for (i = 0; i < max_streams; i++) {
+		ret = uasp_alloc_stream_res(fu, &fu->stream[i]);
+		if (ret)
+			goto err_cleanup;
+	}
+
+	ret = uasp_alloc_cmd(fu);
+	if (ret)
+		goto err_free_stream;
+	uasp_setup_stream_res(fu, max_streams);
+
+	ret = usb_ep_queue(fu->ep_cmd, fu->cmd.req, GFP_ATOMIC);
+	if (ret)
+		goto err_free_stream;
+
+	return 0;
+
+err_free_stream:
+	uasp_free_cmdreq(fu);
+
+err_cleanup:
+	if (i) {
+		do {
+			uasp_cleanup_one_stream(fu, &fu->stream[i - 1]);
+			i--;
+		} while (i);
+	}
+	pr_err("UASP: endpoint setup failed\n");
+	return ret;
+}
+
+static void uasp_set_alt(struct f_uas *fu)
+{
+	struct usb_function *f = &fu->function;
+	struct usb_gadget *gadget = f->config->cdev->gadget;
+	int ret;
+
+	fu->flags = USBG_IS_UAS;
+
+	if (gadget->speed >= USB_SPEED_SUPER)
+		fu->flags |= USBG_USE_STREAMS;
+
+	config_ep_by_speed_and_alt(gadget, f, fu->ep_in, USB_G_ALT_INT_UAS);
+	ret = usb_ep_enable(fu->ep_in);
+	if (ret)
+		goto err_b_in;
+
+	config_ep_by_speed_and_alt(gadget, f, fu->ep_out, USB_G_ALT_INT_UAS);
+	ret = usb_ep_enable(fu->ep_out);
+	if (ret)
+		goto err_b_out;
+
+	config_ep_by_speed_and_alt(gadget, f, fu->ep_cmd, USB_G_ALT_INT_UAS);
+	ret = usb_ep_enable(fu->ep_cmd);
+	if (ret)
+		goto err_cmd;
+	config_ep_by_speed_and_alt(gadget, f, fu->ep_status, USB_G_ALT_INT_UAS);
+	ret = usb_ep_enable(fu->ep_status);
+	if (ret)
+		goto err_status;
+
+	ret = uasp_prepare_reqs(fu);
+	if (ret)
+		goto err_wq;
+	fu->flags |= USBG_ENABLED;
+
+	pr_info("Using the UAS protocol\n");
+	return;
+err_wq:
+	usb_ep_disable(fu->ep_status);
+err_status:
+	usb_ep_disable(fu->ep_cmd);
+err_cmd:
+	usb_ep_disable(fu->ep_out);
+err_b_out:
+	usb_ep_disable(fu->ep_in);
+err_b_in:
+	fu->flags = 0;
+}
+
+static int get_cmd_dir(const unsigned char *cdb)
+{
+	int ret;
+
+	switch (cdb[0]) {
+	case READ_6:
+	case READ_10:
+	case READ_12:
+	case READ_16:
+	case INQUIRY:
+	case MODE_SENSE:
+	case MODE_SENSE_10:
+	case SERVICE_ACTION_IN_16:
+	case MAINTENANCE_IN:
+	case PERSISTENT_RESERVE_IN:
+	case SECURITY_PROTOCOL_IN:
+	case ACCESS_CONTROL_IN:
+	case REPORT_LUNS:
+	case READ_BLOCK_LIMITS:
+	case READ_POSITION:
+	case READ_CAPACITY:
+	case READ_TOC:
+	case READ_FORMAT_CAPACITIES:
+	case REQUEST_SENSE:
+		ret = DMA_FROM_DEVICE;
+		break;
+
+	case WRITE_6:
+	case WRITE_10:
+	case WRITE_12:
+	case WRITE_16:
+	case MODE_SELECT:
+	case MODE_SELECT_10:
+	case WRITE_VERIFY:
+	case WRITE_VERIFY_12:
+	case PERSISTENT_RESERVE_OUT:
+	case MAINTENANCE_OUT:
+	case SECURITY_PROTOCOL_OUT:
+	case ACCESS_CONTROL_OUT:
+		ret = DMA_TO_DEVICE;
+		break;
+	case ALLOW_MEDIUM_REMOVAL:
+	case TEST_UNIT_READY:
+	case SYNCHRONIZE_CACHE:
+	case START_STOP:
+	case ERASE:
+	case REZERO_UNIT:
+	case SEEK_10:
+	case SPACE:
+	case VERIFY:
+	case WRITE_FILEMARKS:
+		ret = DMA_NONE;
+		break;
+	default:
+#define CMD_DIR_MSG "target: Unknown data direction for SCSI Opcode 0x%02x\n"
+		pr_warn(CMD_DIR_MSG, cdb[0]);
+#undef CMD_DIR_MSG
+		ret = -EINVAL;
+	}
+	return ret;
+}
+
+static void usbg_data_write_cmpl(struct usb_ep *ep, struct usb_request *req)
+{
+	struct usbg_cmd *cmd = req->context;
+	struct se_cmd *se_cmd = &cmd->se_cmd;
+
+	if (req->status < 0) {
+		pr_err("%s() state %d transfer failed\n", __func__, cmd->state);
+		goto cleanup;
+	}
+
+	if (req->num_sgs == 0) {
+		sg_copy_from_buffer(se_cmd->t_data_sg,
+				se_cmd->t_data_nents,
+				cmd->data_buf,
+				se_cmd->data_length);
+	}
+
+	complete(&cmd->write_complete);
+	return;
+
+cleanup:
+	transport_generic_free_cmd(&cmd->se_cmd, 0);
+}
+
+static int usbg_prepare_w_request(struct usbg_cmd *cmd, struct usb_request *req)
+{
+	struct se_cmd *se_cmd = &cmd->se_cmd;
+	struct f_uas *fu = cmd->fu;
+	struct usb_gadget *gadget = fuas_to_gadget(fu);
+
+	if (!gadget->sg_supported) {
+		cmd->data_buf = kmalloc(se_cmd->data_length, GFP_ATOMIC);
+		if (!cmd->data_buf)
+			return -ENOMEM;
+
+		req->buf = cmd->data_buf;
+	} else {
+		req->buf = NULL;
+		req->num_sgs = se_cmd->t_data_nents;
+		req->sg = se_cmd->t_data_sg;
+	}
+
+	req->is_last = 1;
+	req->complete = usbg_data_write_cmpl;
+	req->length = se_cmd->data_length;
+	req->context = cmd;
+	return 0;
+}
+
+static int usbg_send_status_response(struct se_cmd *se_cmd)
+{
+	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,
+			se_cmd);
+	struct f_uas *fu = cmd->fu;
+
+	if (fu->flags & USBG_IS_BOT)
+		return bot_send_status_response(cmd);
+	else
+		return uasp_send_status_response(cmd);
+}
+
+static int usbg_send_write_request(struct se_cmd *se_cmd)
+{
+	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,
+			se_cmd);
+	struct f_uas *fu = cmd->fu;
+
+	if (fu->flags & USBG_IS_BOT)
+		return bot_send_write_request(cmd);
+	else
+		return uasp_send_write_request(cmd);
+}
+
+static int usbg_send_read_response(struct se_cmd *se_cmd)
+{
+	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,
+			se_cmd);
+	struct f_uas *fu = cmd->fu;
+
+	if (fu->flags & USBG_IS_BOT)
+		return bot_send_read_response(cmd);
+	else
+		return uasp_send_read_response(cmd);
+}
+
+static void usbg_cmd_work(struct work_struct *work)
+{
+	struct usbg_cmd *cmd = container_of(work, struct usbg_cmd, work);
+	struct se_cmd *se_cmd;
+	struct tcm_usbg_nexus *tv_nexus;
+	struct usbg_tpg *tpg;
+	int dir, flags = (TARGET_SCF_UNKNOWN_SIZE | TARGET_SCF_ACK_KREF);
+
+	se_cmd = &cmd->se_cmd;
+	tpg = cmd->fu->tpg;
+	tv_nexus = tpg->tpg_nexus;
+	dir = get_cmd_dir(cmd->cmd_buf);
+	if (dir < 0) {
+		__target_init_cmd(se_cmd,
+				  tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
+				  tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
+				  cmd->prio_attr, cmd->sense_iu.sense,
+				  cmd->unpacked_lun, NULL);
+		goto out;
+	}
+
+	target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess, cmd->cmd_buf,
+			  cmd->sense_iu.sense, cmd->unpacked_lun, 0,
+			  cmd->prio_attr, dir, flags);
+	return;
+
+out:
+	transport_send_check_condition_and_sense(se_cmd,
+			TCM_UNSUPPORTED_SCSI_OPCODE, 1);
+	transport_generic_free_cmd(&cmd->se_cmd, 0);
+}
+
+static struct usbg_cmd *usbg_get_cmd(struct f_uas *fu,
+		struct tcm_usbg_nexus *tv_nexus, u32 scsi_tag)
+{
+	struct se_session *se_sess = tv_nexus->tvn_se_sess;
+	struct usbg_cmd *cmd;
+	int tag, cpu;
+
+	tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
+	if (tag < 0)
+		return ERR_PTR(-ENOMEM);
+
+	cmd = &((struct usbg_cmd *)se_sess->sess_cmd_map)[tag];
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->se_cmd.map_tag = tag;
+	cmd->se_cmd.map_cpu = cpu;
+	cmd->se_cmd.tag = cmd->tag = scsi_tag;
+	cmd->fu = fu;
+
+	return cmd;
+}
+
+static void usbg_release_cmd(struct se_cmd *);
+
+static int usbg_submit_command(struct f_uas *fu,
+		void *cmdbuf, unsigned int len)
+{
+	struct command_iu *cmd_iu = cmdbuf;
+	struct usbg_cmd *cmd;
+	struct usbg_tpg *tpg = fu->tpg;
+	struct tcm_usbg_nexus *tv_nexus;
+	u32 cmd_len;
+	u16 scsi_tag;
+
+	if (cmd_iu->iu_id != IU_ID_COMMAND) {
+		pr_err("Unsupported type %d\n", cmd_iu->iu_id);
+		return -EINVAL;
+	}
+
+	tv_nexus = tpg->tpg_nexus;
+	if (!tv_nexus) {
+		pr_err("Missing nexus, ignoring command\n");
+		return -EINVAL;
+	}
+
+	cmd_len = (cmd_iu->len & ~0x3) + 16;
+	if (cmd_len > USBG_MAX_CMD)
+		return -EINVAL;
+
+	scsi_tag = be16_to_cpup(&cmd_iu->tag);
+	cmd = usbg_get_cmd(fu, tv_nexus, scsi_tag);
+	if (IS_ERR(cmd)) {
+		pr_err("usbg_get_cmd failed\n");
+		return -ENOMEM;
+	}
+	memcpy(cmd->cmd_buf, cmd_iu->cdb, cmd_len);
+
+	if (fu->flags & USBG_USE_STREAMS) {
+		if (cmd->tag > UASP_SS_EP_COMP_NUM_STREAMS)
+			goto err;
+		if (!cmd->tag)
+			cmd->stream = &fu->stream[0];
+		else
+			cmd->stream = &fu->stream[cmd->tag - 1];
+	} else {
+		cmd->stream = &fu->stream[0];
+	}
+
+	switch (cmd_iu->prio_attr & 0x7) {
+	case UAS_HEAD_TAG:
+		cmd->prio_attr = TCM_HEAD_TAG;
+		break;
+	case UAS_ORDERED_TAG:
+		cmd->prio_attr = TCM_ORDERED_TAG;
+		break;
+	case UAS_ACA:
+		cmd->prio_attr = TCM_ACA_TAG;
+		break;
+	default:
+		pr_debug_once("Unsupported prio_attr: %02x.\n",
+				cmd_iu->prio_attr);
+		fallthrough;
+	case UAS_SIMPLE_TAG:
+		cmd->prio_attr = TCM_SIMPLE_TAG;
+		break;
+	}
+
+	cmd->unpacked_lun = scsilun_to_int(&cmd_iu->lun);
+
+	INIT_WORK(&cmd->work, usbg_cmd_work);
+	queue_work(tpg->workqueue, &cmd->work);
+
+	return 0;
+err:
+	usbg_release_cmd(&cmd->se_cmd);
+	return -EINVAL;
+}
+
+static void bot_cmd_work(struct work_struct *work)
+{
+	struct usbg_cmd *cmd = container_of(work, struct usbg_cmd, work);
+	struct se_cmd *se_cmd;
+	struct tcm_usbg_nexus *tv_nexus;
+	struct usbg_tpg *tpg;
+	int dir;
+
+	se_cmd = &cmd->se_cmd;
+	tpg = cmd->fu->tpg;
+	tv_nexus = tpg->tpg_nexus;
+	dir = get_cmd_dir(cmd->cmd_buf);
+	if (dir < 0) {
+		__target_init_cmd(se_cmd,
+				  tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
+				  tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
+				  cmd->prio_attr, cmd->sense_iu.sense,
+				  cmd->unpacked_lun, NULL);
+		goto out;
+	}
+
+	target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
+			  cmd->cmd_buf, cmd->sense_iu.sense, cmd->unpacked_lun,
+			  cmd->data_len, cmd->prio_attr, dir, 0);
+	return;
+
+out:
+	transport_send_check_condition_and_sense(se_cmd,
+				TCM_UNSUPPORTED_SCSI_OPCODE, 1);
+	transport_generic_free_cmd(&cmd->se_cmd, 0);
+}
+
+static int bot_submit_command(struct f_uas *fu,
+		void *cmdbuf, unsigned int len)
+{
+	struct bulk_cb_wrap *cbw = cmdbuf;
+	struct usbg_cmd *cmd;
+	struct usbg_tpg *tpg = fu->tpg;
+	struct tcm_usbg_nexus *tv_nexus;
+	u32 cmd_len;
+
+	if (cbw->Signature != cpu_to_le32(US_BULK_CB_SIGN)) {
+		pr_err("Wrong signature on CBW\n");
+		return -EINVAL;
+	}
+	if (len != 31) {
+		pr_err("Wrong length for CBW\n");
+		return -EINVAL;
+	}
+
+	cmd_len = cbw->Length;
+	if (cmd_len < 1 || cmd_len > 16)
+		return -EINVAL;
+
+	tv_nexus = tpg->tpg_nexus;
+	if (!tv_nexus) {
+		pr_err("Missing nexus, ignoring command\n");
+		return -ENODEV;
+	}
+
+	cmd = usbg_get_cmd(fu, tv_nexus, cbw->Tag);
+	if (IS_ERR(cmd)) {
+		pr_err("usbg_get_cmd failed\n");
+		return -ENOMEM;
+	}
+	memcpy(cmd->cmd_buf, cbw->CDB, cmd_len);
+
+	cmd->bot_tag = cbw->Tag;
+	cmd->prio_attr = TCM_SIMPLE_TAG;
+	cmd->unpacked_lun = cbw->Lun;
+	cmd->is_read = cbw->Flags & US_BULK_FLAG_IN ? 1 : 0;
+	cmd->data_len = le32_to_cpu(cbw->DataTransferLength);
+	cmd->se_cmd.tag = le32_to_cpu(cmd->bot_tag);
+
+	INIT_WORK(&cmd->work, bot_cmd_work);
+	queue_work(tpg->workqueue, &cmd->work);
+
+	return 0;
+}
+
+/* Start fabric.c code */
+
+static int usbg_check_true(struct se_portal_group *se_tpg)
+{
+	return 1;
+}
+
+static int usbg_check_false(struct se_portal_group *se_tpg)
+{
+	return 0;
+}
+
+static char *usbg_get_fabric_wwn(struct se_portal_group *se_tpg)
+{
+	struct usbg_tpg *tpg = container_of(se_tpg,
+				struct usbg_tpg, se_tpg);
+	struct usbg_tport *tport = tpg->tport;
+
+	return &tport->tport_name[0];
+}
+
+static u16 usbg_get_tag(struct se_portal_group *se_tpg)
+{
+	struct usbg_tpg *tpg = container_of(se_tpg,
+				struct usbg_tpg, se_tpg);
+	return tpg->tport_tpgt;
+}
+
+static u32 usbg_tpg_get_inst_index(struct se_portal_group *se_tpg)
+{
+	return 1;
+}
+
+static void usbg_release_cmd(struct se_cmd *se_cmd)
+{
+	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,
+			se_cmd);
+	struct se_session *se_sess = se_cmd->se_sess;
+
+	kfree(cmd->data_buf);
+	target_free_tag(se_sess, se_cmd);
+}
+
+static u32 usbg_sess_get_index(struct se_session *se_sess)
+{
+	return 0;
+}
+
+static void usbg_set_default_node_attrs(struct se_node_acl *nacl)
+{
+}
+
+static int usbg_get_cmd_state(struct se_cmd *se_cmd)
+{
+	return 0;
+}
+
+static void usbg_queue_tm_rsp(struct se_cmd *se_cmd)
+{
+}
+
+static void usbg_aborted_task(struct se_cmd *se_cmd)
+{
+}
+
+static const char *usbg_check_wwn(const char *name)
+{
+	const char *n;
+	unsigned int len;
+
+	n = strstr(name, "naa.");
+	if (!n)
+		return NULL;
+	n += 4;
+	len = strlen(n);
+	if (len == 0 || len > USBG_NAMELEN - 1)
+		return NULL;
+	return n;
+}
+
+static int usbg_init_nodeacl(struct se_node_acl *se_nacl, const char *name)
+{
+	if (!usbg_check_wwn(name))
+		return -EINVAL;
+	return 0;
+}
+
+static struct se_portal_group *usbg_make_tpg(struct se_wwn *wwn,
+					     const char *name)
+{
+	struct usbg_tport *tport = container_of(wwn, struct usbg_tport,
+			tport_wwn);
+	struct usbg_tpg *tpg;
+	unsigned long tpgt;
+	int ret;
+	struct f_tcm_opts *opts;
+	unsigned i;
+
+	if (strstr(name, "tpgt_") != name)
+		return ERR_PTR(-EINVAL);
+	if (kstrtoul(name + 5, 0, &tpgt) || tpgt > UINT_MAX)
+		return ERR_PTR(-EINVAL);
+	ret = -ENODEV;
+	mutex_lock(&tpg_instances_lock);
+	for (i = 0; i < TPG_INSTANCES; ++i)
+		if (tpg_instances[i].func_inst && !tpg_instances[i].tpg)
+			break;
+	if (i == TPG_INSTANCES)
+		goto unlock_inst;
+
+	opts = container_of(tpg_instances[i].func_inst, struct f_tcm_opts,
+		func_inst);
+	mutex_lock(&opts->dep_lock);
+	if (!opts->ready)
+		goto unlock_dep;
+
+	if (opts->has_dep) {
+		if (!try_module_get(opts->dependent))
+			goto unlock_dep;
+	} else {
+		ret = configfs_depend_item_unlocked(
+			wwn->wwn_group.cg_subsys,
+			&opts->func_inst.group.cg_item);
+		if (ret)
+			goto unlock_dep;
+	}
+
+	tpg = kzalloc(sizeof(struct usbg_tpg), GFP_KERNEL);
+	ret = -ENOMEM;
+	if (!tpg)
+		goto unref_dep;
+	mutex_init(&tpg->tpg_mutex);
+	atomic_set(&tpg->tpg_port_count, 0);
+	tpg->workqueue = alloc_workqueue("tcm_usb_gadget", 0, 1);
+	if (!tpg->workqueue)
+		goto free_tpg;
+
+	tpg->tport = tport;
+	tpg->tport_tpgt = tpgt;
+
+	/*
+	 * SPC doesn't assign a protocol identifier for USB-SCSI, so we
+	 * pretend to be SAS..
+	 */
+	ret = core_tpg_register(wwn, &tpg->se_tpg, SCSI_PROTOCOL_SAS);
+	if (ret < 0)
+		goto free_workqueue;
+
+	tpg_instances[i].tpg = tpg;
+	tpg->fi = tpg_instances[i].func_inst;
+	mutex_unlock(&opts->dep_lock);
+	mutex_unlock(&tpg_instances_lock);
+	return &tpg->se_tpg;
+
+free_workqueue:
+	destroy_workqueue(tpg->workqueue);
+free_tpg:
+	kfree(tpg);
+unref_dep:
+	if (opts->has_dep)
+		module_put(opts->dependent);
+	else
+		configfs_undepend_item_unlocked(&opts->func_inst.group.cg_item);
+unlock_dep:
+	mutex_unlock(&opts->dep_lock);
+unlock_inst:
+	mutex_unlock(&tpg_instances_lock);
+
+	return ERR_PTR(ret);
+}
+
+static int tcm_usbg_drop_nexus(struct usbg_tpg *);
+
+static void usbg_drop_tpg(struct se_portal_group *se_tpg)
+{
+	struct usbg_tpg *tpg = container_of(se_tpg,
+				struct usbg_tpg, se_tpg);
+	unsigned i;
+	struct f_tcm_opts *opts;
+
+	tcm_usbg_drop_nexus(tpg);
+	core_tpg_deregister(se_tpg);
+	destroy_workqueue(tpg->workqueue);
+
+	mutex_lock(&tpg_instances_lock);
+	for (i = 0; i < TPG_INSTANCES; ++i)
+		if (tpg_instances[i].tpg == tpg)
+			break;
+	if (i < TPG_INSTANCES) {
+		tpg_instances[i].tpg = NULL;
+		opts = container_of(tpg_instances[i].func_inst,
+			struct f_tcm_opts, func_inst);
+		mutex_lock(&opts->dep_lock);
+		if (opts->has_dep)
+			module_put(opts->dependent);
+		else
+			configfs_undepend_item_unlocked(
+				&opts->func_inst.group.cg_item);
+		mutex_unlock(&opts->dep_lock);
+	}
+	mutex_unlock(&tpg_instances_lock);
+
+	kfree(tpg);
+}
+
+static struct se_wwn *usbg_make_tport(
+	struct target_fabric_configfs *tf,
+	struct config_group *group,
+	const char *name)
+{
+	struct usbg_tport *tport;
+	const char *wnn_name;
+	u64 wwpn = 0;
+
+	wnn_name = usbg_check_wwn(name);
+	if (!wnn_name)
+		return ERR_PTR(-EINVAL);
+
+	tport = kzalloc(sizeof(struct usbg_tport), GFP_KERNEL);
+	if (!(tport))
+		return ERR_PTR(-ENOMEM);
+
+	tport->tport_wwpn = wwpn;
+	snprintf(tport->tport_name, sizeof(tport->tport_name), "%s", wnn_name);
+	return &tport->tport_wwn;
+}
+
+static void usbg_drop_tport(struct se_wwn *wwn)
+{
+	struct usbg_tport *tport = container_of(wwn,
+				struct usbg_tport, tport_wwn);
+	kfree(tport);
+}
+
+/*
+ * If somebody feels like dropping the version property, go ahead.
+ */
+static ssize_t usbg_wwn_version_show(struct config_item *item,  char *page)
+{
+	return sprintf(page, "usb-gadget fabric module\n");
+}
+
+CONFIGFS_ATTR_RO(usbg_wwn_, version);
+
+static struct configfs_attribute *usbg_wwn_attrs[] = {
+	&usbg_wwn_attr_version,
+	NULL,
+};
+
+static int usbg_attach(struct usbg_tpg *);
+static void usbg_detach(struct usbg_tpg *);
+
+static int usbg_enable_tpg(struct se_portal_group *se_tpg, bool enable)
+{
+	struct usbg_tpg  *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
+	int ret = 0;
+
+	if (enable)
+		ret = usbg_attach(tpg);
+	else
+		usbg_detach(tpg);
+	if (ret)
+		return ret;
+
+	tpg->gadget_connect = enable;
+
+	return 0;
+}
+
+static ssize_t tcm_usbg_tpg_nexus_show(struct config_item *item, char *page)
+{
+	struct se_portal_group *se_tpg = to_tpg(item);
+	struct usbg_tpg *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
+	struct tcm_usbg_nexus *tv_nexus;
+	ssize_t ret;
+
+	mutex_lock(&tpg->tpg_mutex);
+	tv_nexus = tpg->tpg_nexus;
+	if (!tv_nexus) {
+		ret = -ENODEV;
+		goto out;
+	}
+	ret = snprintf(page, PAGE_SIZE, "%s\n",
+			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
+out:
+	mutex_unlock(&tpg->tpg_mutex);
+	return ret;
+}
+
+static int usbg_alloc_sess_cb(struct se_portal_group *se_tpg,
+			      struct se_session *se_sess, void *p)
+{
+	struct usbg_tpg *tpg = container_of(se_tpg,
+				struct usbg_tpg, se_tpg);
+
+	tpg->tpg_nexus = p;
+	return 0;
+}
+
+static int tcm_usbg_make_nexus(struct usbg_tpg *tpg, char *name)
+{
+	struct tcm_usbg_nexus *tv_nexus;
+	int ret = 0;
+
+	mutex_lock(&tpg->tpg_mutex);
+	if (tpg->tpg_nexus) {
+		ret = -EEXIST;
+		pr_debug("tpg->tpg_nexus already exists\n");
+		goto out_unlock;
+	}
+
+	tv_nexus = kzalloc(sizeof(*tv_nexus), GFP_KERNEL);
+	if (!tv_nexus) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
+
+	tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
+						     USB_G_DEFAULT_SESSION_TAGS,
+						     sizeof(struct usbg_cmd),
+						     TARGET_PROT_NORMAL, name,
+						     tv_nexus, usbg_alloc_sess_cb);
+	if (IS_ERR(tv_nexus->tvn_se_sess)) {
+#define MAKE_NEXUS_MSG "core_tpg_check_initiator_node_acl() failed for %s\n"
+		pr_debug(MAKE_NEXUS_MSG, name);
+#undef MAKE_NEXUS_MSG
+		ret = PTR_ERR(tv_nexus->tvn_se_sess);
+		kfree(tv_nexus);
+	}
+
+out_unlock:
+	mutex_unlock(&tpg->tpg_mutex);
+	return ret;
+}
+
+static int tcm_usbg_drop_nexus(struct usbg_tpg *tpg)
+{
+	struct se_session *se_sess;
+	struct tcm_usbg_nexus *tv_nexus;
+	int ret = -ENODEV;
+
+	mutex_lock(&tpg->tpg_mutex);
+	tv_nexus = tpg->tpg_nexus;
+	if (!tv_nexus)
+		goto out;
+
+	se_sess = tv_nexus->tvn_se_sess;
+	if (!se_sess)
+		goto out;
+
+	if (atomic_read(&tpg->tpg_port_count)) {
+		ret = -EPERM;
+#define MSG "Unable to remove Host I_T Nexus with active TPG port count: %d\n"
+		pr_err(MSG, atomic_read(&tpg->tpg_port_count));
+#undef MSG
+		goto out;
+	}
+
+	pr_debug("Removing I_T Nexus to Initiator Port: %s\n",
+			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
+	/*
+	 * Release the SCSI I_T Nexus to the emulated vHost Target Port
+	 */
+	target_remove_session(se_sess);
+	tpg->tpg_nexus = NULL;
+
+	kfree(tv_nexus);
+	ret = 0;
+out:
+	mutex_unlock(&tpg->tpg_mutex);
+	return ret;
+}
+
+static ssize_t tcm_usbg_tpg_nexus_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct se_portal_group *se_tpg = to_tpg(item);
+	struct usbg_tpg *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
+	unsigned char i_port[USBG_NAMELEN], *ptr;
+	int ret;
+
+	if (!strncmp(page, "NULL", 4)) {
+		ret = tcm_usbg_drop_nexus(tpg);
+		return (!ret) ? count : ret;
+	}
+	if (strlen(page) >= USBG_NAMELEN) {
+
+#define NEXUS_STORE_MSG "Emulated NAA Sas Address: %s, exceeds max: %d\n"
+		pr_err(NEXUS_STORE_MSG, page, USBG_NAMELEN);
+#undef NEXUS_STORE_MSG
+		return -EINVAL;
+	}
+	snprintf(i_port, USBG_NAMELEN, "%s", page);
+
+	ptr = strstr(i_port, "naa.");
+	if (!ptr) {
+		pr_err("Missing 'naa.' prefix\n");
+		return -EINVAL;
+	}
+
+	if (i_port[strlen(i_port) - 1] == '\n')
+		i_port[strlen(i_port) - 1] = '\0';
+
+	ret = tcm_usbg_make_nexus(tpg, &i_port[0]);
+	if (ret < 0)
+		return ret;
+	return count;
+}
+
+CONFIGFS_ATTR(tcm_usbg_tpg_, nexus);
+
+static struct configfs_attribute *usbg_base_attrs[] = {
+	&tcm_usbg_tpg_attr_nexus,
+	NULL,
+};
+
+static int usbg_port_link(struct se_portal_group *se_tpg, struct se_lun *lun)
+{
+	struct usbg_tpg *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
+
+	atomic_inc(&tpg->tpg_port_count);
+	smp_mb__after_atomic();
+	return 0;
+}
+
+static void usbg_port_unlink(struct se_portal_group *se_tpg,
+		struct se_lun *se_lun)
+{
+	struct usbg_tpg *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
+
+	atomic_dec(&tpg->tpg_port_count);
+	smp_mb__after_atomic();
+}
+
+static int usbg_check_stop_free(struct se_cmd *se_cmd)
+{
+	return target_put_sess_cmd(se_cmd);
+}
+
+static const struct target_core_fabric_ops usbg_ops = {
+	.module				= THIS_MODULE,
+	.fabric_name			= "usb_gadget",
+	.tpg_get_wwn			= usbg_get_fabric_wwn,
+	.tpg_get_tag			= usbg_get_tag,
+	.tpg_check_demo_mode		= usbg_check_true,
+	.tpg_check_demo_mode_cache	= usbg_check_false,
+	.tpg_check_demo_mode_write_protect = usbg_check_false,
+	.tpg_check_prod_mode_write_protect = usbg_check_false,
+	.tpg_get_inst_index		= usbg_tpg_get_inst_index,
+	.release_cmd			= usbg_release_cmd,
+	.sess_get_index			= usbg_sess_get_index,
+	.sess_get_initiator_sid		= NULL,
+	.write_pending			= usbg_send_write_request,
+	.set_default_node_attributes	= usbg_set_default_node_attrs,
+	.get_cmd_state			= usbg_get_cmd_state,
+	.queue_data_in			= usbg_send_read_response,
+	.queue_status			= usbg_send_status_response,
+	.queue_tm_rsp			= usbg_queue_tm_rsp,
+	.aborted_task			= usbg_aborted_task,
+	.check_stop_free		= usbg_check_stop_free,
+
+	.fabric_make_wwn		= usbg_make_tport,
+	.fabric_drop_wwn		= usbg_drop_tport,
+	.fabric_make_tpg		= usbg_make_tpg,
+	.fabric_enable_tpg		= usbg_enable_tpg,
+	.fabric_drop_tpg		= usbg_drop_tpg,
+	.fabric_post_link		= usbg_port_link,
+	.fabric_pre_unlink		= usbg_port_unlink,
+	.fabric_init_nodeacl		= usbg_init_nodeacl,
+
+	.tfc_wwn_attrs			= usbg_wwn_attrs,
+	.tfc_tpg_base_attrs		= usbg_base_attrs,
+};
+
+/* Start gadget.c code */
+
+static struct usb_interface_descriptor bot_intf_desc = {
+	.bLength =              sizeof(bot_intf_desc),
+	.bDescriptorType =      USB_DT_INTERFACE,
+	.bNumEndpoints =        2,
+	.bAlternateSetting =	USB_G_ALT_INT_BBB,
+	.bInterfaceClass =      USB_CLASS_MASS_STORAGE,
+	.bInterfaceSubClass =   USB_SC_SCSI,
+	.bInterfaceProtocol =   USB_PR_BULK,
+};
+
+static struct usb_interface_descriptor uasp_intf_desc = {
+	.bLength =		sizeof(uasp_intf_desc),
+	.bDescriptorType =	USB_DT_INTERFACE,
+	.bNumEndpoints =	4,
+	.bAlternateSetting =	USB_G_ALT_INT_UAS,
+	.bInterfaceClass =	USB_CLASS_MASS_STORAGE,
+	.bInterfaceSubClass =	USB_SC_SCSI,
+	.bInterfaceProtocol =	USB_PR_UAS,
+};
+
+static struct usb_endpoint_descriptor uasp_bi_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor uasp_fs_bi_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_pipe_usage_descriptor uasp_bi_pipe_desc = {
+	.bLength =		sizeof(uasp_bi_pipe_desc),
+	.bDescriptorType =	USB_DT_PIPE_USAGE,
+	.bPipeID =		DATA_IN_PIPE_ID,
+};
+
+static struct usb_endpoint_descriptor uasp_ss_bi_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor uasp_bi_ep_comp_desc = {
+	.bLength =		sizeof(uasp_bi_ep_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+	.bMaxBurst =		0,
+	.bmAttributes =		UASP_SS_EP_COMP_LOG_STREAMS,
+	.wBytesPerInterval =	0,
+};
+
+static struct usb_ss_ep_comp_descriptor bot_bi_ep_comp_desc = {
+	.bLength =		sizeof(bot_bi_ep_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+	.bMaxBurst =		0,
+};
+
+static struct usb_endpoint_descriptor uasp_bo_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor uasp_fs_bo_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_pipe_usage_descriptor uasp_bo_pipe_desc = {
+	.bLength =		sizeof(uasp_bo_pipe_desc),
+	.bDescriptorType =	USB_DT_PIPE_USAGE,
+	.bPipeID =		DATA_OUT_PIPE_ID,
+};
+
+static struct usb_endpoint_descriptor uasp_ss_bo_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(0x400),
+};
+
+static struct usb_ss_ep_comp_descriptor uasp_bo_ep_comp_desc = {
+	.bLength =		sizeof(uasp_bo_ep_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+	.bmAttributes =		UASP_SS_EP_COMP_LOG_STREAMS,
+};
+
+static struct usb_ss_ep_comp_descriptor bot_bo_ep_comp_desc = {
+	.bLength =		sizeof(bot_bo_ep_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+};
+
+static struct usb_endpoint_descriptor uasp_status_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor uasp_fs_status_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_pipe_usage_descriptor uasp_status_pipe_desc = {
+	.bLength =		sizeof(uasp_status_pipe_desc),
+	.bDescriptorType =	USB_DT_PIPE_USAGE,
+	.bPipeID =		STATUS_PIPE_ID,
+};
+
+static struct usb_endpoint_descriptor uasp_ss_status_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor uasp_status_in_ep_comp_desc = {
+	.bLength =		sizeof(uasp_status_in_ep_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+	.bmAttributes =		UASP_SS_EP_COMP_LOG_STREAMS,
+};
+
+static struct usb_endpoint_descriptor uasp_cmd_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor uasp_fs_cmd_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_pipe_usage_descriptor uasp_cmd_pipe_desc = {
+	.bLength =		sizeof(uasp_cmd_pipe_desc),
+	.bDescriptorType =	USB_DT_PIPE_USAGE,
+	.bPipeID =		CMD_PIPE_ID,
+};
+
+static struct usb_endpoint_descriptor uasp_ss_cmd_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor uasp_cmd_comp_desc = {
+	.bLength =		sizeof(uasp_cmd_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+};
+
+static struct usb_descriptor_header *uasp_fs_function_desc[] = {
+	(struct usb_descriptor_header *) &bot_intf_desc,
+	(struct usb_descriptor_header *) &uasp_fs_bi_desc,
+	(struct usb_descriptor_header *) &uasp_fs_bo_desc,
+
+	(struct usb_descriptor_header *) &uasp_intf_desc,
+	(struct usb_descriptor_header *) &uasp_fs_bi_desc,
+	(struct usb_descriptor_header *) &uasp_bi_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_fs_bo_desc,
+	(struct usb_descriptor_header *) &uasp_bo_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_fs_status_desc,
+	(struct usb_descriptor_header *) &uasp_status_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_fs_cmd_desc,
+	(struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
+	NULL,
+};
+
+static struct usb_descriptor_header *uasp_hs_function_desc[] = {
+	(struct usb_descriptor_header *) &bot_intf_desc,
+	(struct usb_descriptor_header *) &uasp_bi_desc,
+	(struct usb_descriptor_header *) &uasp_bo_desc,
+
+	(struct usb_descriptor_header *) &uasp_intf_desc,
+	(struct usb_descriptor_header *) &uasp_bi_desc,
+	(struct usb_descriptor_header *) &uasp_bi_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_bo_desc,
+	(struct usb_descriptor_header *) &uasp_bo_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_status_desc,
+	(struct usb_descriptor_header *) &uasp_status_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_cmd_desc,
+	(struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
+	NULL,
+};
+
+static struct usb_descriptor_header *uasp_ss_function_desc[] = {
+	(struct usb_descriptor_header *) &bot_intf_desc,
+	(struct usb_descriptor_header *) &uasp_ss_bi_desc,
+	(struct usb_descriptor_header *) &bot_bi_ep_comp_desc,
+	(struct usb_descriptor_header *) &uasp_ss_bo_desc,
+	(struct usb_descriptor_header *) &bot_bo_ep_comp_desc,
+
+	(struct usb_descriptor_header *) &uasp_intf_desc,
+	(struct usb_descriptor_header *) &uasp_ss_bi_desc,
+	(struct usb_descriptor_header *) &uasp_bi_ep_comp_desc,
+	(struct usb_descriptor_header *) &uasp_bi_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_ss_bo_desc,
+	(struct usb_descriptor_header *) &uasp_bo_ep_comp_desc,
+	(struct usb_descriptor_header *) &uasp_bo_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_ss_status_desc,
+	(struct usb_descriptor_header *) &uasp_status_in_ep_comp_desc,
+	(struct usb_descriptor_header *) &uasp_status_pipe_desc,
+	(struct usb_descriptor_header *) &uasp_ss_cmd_desc,
+	(struct usb_descriptor_header *) &uasp_cmd_comp_desc,
+	(struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
+	NULL,
+};
+
+static struct usb_string	tcm_us_strings[] = {
+	[USB_G_STR_INT_UAS].s		= "USB Attached SCSI",
+	[USB_G_STR_INT_BBB].s		= "Bulk Only Transport",
+	{ },
+};
+
+static struct usb_gadget_strings tcm_stringtab = {
+	.language = 0x0409,
+	.strings = tcm_us_strings,
+};
+
+static struct usb_gadget_strings *tcm_strings[] = {
+	&tcm_stringtab,
+	NULL,
+};
+
+static int tcm_bind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct f_uas		*fu = to_f_uas(f);
+	struct usb_string	*us;
+	struct usb_gadget	*gadget = c->cdev->gadget;
+	struct usb_ep		*ep;
+	struct f_tcm_opts	*opts;
+	int			iface;
+	int			ret;
+
+	opts = container_of(f->fi, struct f_tcm_opts, func_inst);
+
+	mutex_lock(&opts->dep_lock);
+	if (!opts->can_attach) {
+		mutex_unlock(&opts->dep_lock);
+		return -ENODEV;
+	}
+	mutex_unlock(&opts->dep_lock);
+	us = usb_gstrings_attach(c->cdev, tcm_strings,
+		ARRAY_SIZE(tcm_us_strings));
+	if (IS_ERR(us))
+		return PTR_ERR(us);
+	bot_intf_desc.iInterface = us[USB_G_STR_INT_BBB].id;
+	uasp_intf_desc.iInterface = us[USB_G_STR_INT_UAS].id;
+
+	iface = usb_interface_id(c, f);
+	if (iface < 0)
+		return iface;
+
+	bot_intf_desc.bInterfaceNumber = iface;
+	uasp_intf_desc.bInterfaceNumber = iface;
+	fu->iface = iface;
+	ep = usb_ep_autoconfig_ss(gadget, &uasp_ss_bi_desc,
+			&uasp_bi_ep_comp_desc);
+	if (!ep)
+		goto ep_fail;
+
+	fu->ep_in = ep;
+
+	ep = usb_ep_autoconfig_ss(gadget, &uasp_ss_bo_desc,
+			&uasp_bo_ep_comp_desc);
+	if (!ep)
+		goto ep_fail;
+	fu->ep_out = ep;
+
+	ep = usb_ep_autoconfig_ss(gadget, &uasp_ss_status_desc,
+			&uasp_status_in_ep_comp_desc);
+	if (!ep)
+		goto ep_fail;
+	fu->ep_status = ep;
+
+	ep = usb_ep_autoconfig_ss(gadget, &uasp_ss_cmd_desc,
+			&uasp_cmd_comp_desc);
+	if (!ep)
+		goto ep_fail;
+	fu->ep_cmd = ep;
+
+	/* Assume endpoint addresses are the same for both speeds */
+	uasp_bi_desc.bEndpointAddress =	uasp_ss_bi_desc.bEndpointAddress;
+	uasp_bo_desc.bEndpointAddress = uasp_ss_bo_desc.bEndpointAddress;
+	uasp_status_desc.bEndpointAddress =
+		uasp_ss_status_desc.bEndpointAddress;
+	uasp_cmd_desc.bEndpointAddress = uasp_ss_cmd_desc.bEndpointAddress;
+
+	uasp_fs_bi_desc.bEndpointAddress = uasp_ss_bi_desc.bEndpointAddress;
+	uasp_fs_bo_desc.bEndpointAddress = uasp_ss_bo_desc.bEndpointAddress;
+	uasp_fs_status_desc.bEndpointAddress =
+		uasp_ss_status_desc.bEndpointAddress;
+	uasp_fs_cmd_desc.bEndpointAddress = uasp_ss_cmd_desc.bEndpointAddress;
+
+	ret = usb_assign_descriptors(f, uasp_fs_function_desc,
+			uasp_hs_function_desc, uasp_ss_function_desc,
+			uasp_ss_function_desc);
+	if (ret)
+		goto ep_fail;
+
+	return 0;
+ep_fail:
+	pr_err("Can't claim all required eps\n");
+
+	return -ENOTSUPP;
+}
+
+struct guas_setup_wq {
+	struct work_struct work;
+	struct f_uas *fu;
+	unsigned int alt;
+};
+
+static void tcm_delayed_set_alt(struct work_struct *wq)
+{
+	struct guas_setup_wq *work = container_of(wq, struct guas_setup_wq,
+			work);
+	struct f_uas *fu = work->fu;
+	int alt = work->alt;
+
+	kfree(work);
+
+	if (fu->flags & USBG_IS_BOT)
+		bot_cleanup_old_alt(fu);
+	if (fu->flags & USBG_IS_UAS)
+		uasp_cleanup_old_alt(fu);
+
+	if (alt == USB_G_ALT_INT_BBB)
+		bot_set_alt(fu);
+	else if (alt == USB_G_ALT_INT_UAS)
+		uasp_set_alt(fu);
+	usb_composite_setup_continue(fu->function.config->cdev);
+}
+
+static int tcm_get_alt(struct usb_function *f, unsigned intf)
+{
+	if (intf == bot_intf_desc.bInterfaceNumber)
+		return USB_G_ALT_INT_BBB;
+	if (intf == uasp_intf_desc.bInterfaceNumber)
+		return USB_G_ALT_INT_UAS;
+
+	return -EOPNOTSUPP;
+}
+
+static int tcm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+	struct f_uas *fu = to_f_uas(f);
+
+	if ((alt == USB_G_ALT_INT_BBB) || (alt == USB_G_ALT_INT_UAS)) {
+		struct guas_setup_wq *work;
+
+		work = kmalloc(sizeof(*work), GFP_ATOMIC);
+		if (!work)
+			return -ENOMEM;
+		INIT_WORK(&work->work, tcm_delayed_set_alt);
+		work->fu = fu;
+		work->alt = alt;
+		schedule_work(&work->work);
+		return USB_GADGET_DELAYED_STATUS;
+	}
+	return -EOPNOTSUPP;
+}
+
+static void tcm_disable(struct usb_function *f)
+{
+	struct f_uas *fu = to_f_uas(f);
+
+	if (fu->flags & USBG_IS_UAS)
+		uasp_cleanup_old_alt(fu);
+	else if (fu->flags & USBG_IS_BOT)
+		bot_cleanup_old_alt(fu);
+	fu->flags = 0;
+}
+
+static int tcm_setup(struct usb_function *f,
+		const struct usb_ctrlrequest *ctrl)
+{
+	struct f_uas *fu = to_f_uas(f);
+
+	if (!(fu->flags & USBG_IS_BOT))
+		return -EOPNOTSUPP;
+
+	return usbg_bot_setup(f, ctrl);
+}
+
+static inline struct f_tcm_opts *to_f_tcm_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_tcm_opts,
+		func_inst.group);
+}
+
+static void tcm_attr_release(struct config_item *item)
+{
+	struct f_tcm_opts *opts = to_f_tcm_opts(item);
+
+	usb_put_function_instance(&opts->func_inst);
+}
+
+static struct configfs_item_operations tcm_item_ops = {
+	.release		= tcm_attr_release,
+};
+
+static const struct config_item_type tcm_func_type = {
+	.ct_item_ops	= &tcm_item_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static void tcm_free_inst(struct usb_function_instance *f)
+{
+	struct f_tcm_opts *opts;
+	unsigned i;
+
+	opts = container_of(f, struct f_tcm_opts, func_inst);
+
+	mutex_lock(&tpg_instances_lock);
+	for (i = 0; i < TPG_INSTANCES; ++i)
+		if (tpg_instances[i].func_inst == f)
+			break;
+	if (i < TPG_INSTANCES)
+		tpg_instances[i].func_inst = NULL;
+	mutex_unlock(&tpg_instances_lock);
+
+	kfree(opts);
+}
+
+static int tcm_register_callback(struct usb_function_instance *f)
+{
+	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
+
+	mutex_lock(&opts->dep_lock);
+	opts->can_attach = true;
+	mutex_unlock(&opts->dep_lock);
+
+	return 0;
+}
+
+static void tcm_unregister_callback(struct usb_function_instance *f)
+{
+	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
+
+	mutex_lock(&opts->dep_lock);
+	unregister_gadget_item(opts->
+		func_inst.group.cg_item.ci_parent->ci_parent);
+	opts->can_attach = false;
+	mutex_unlock(&opts->dep_lock);
+}
+
+static int usbg_attach(struct usbg_tpg *tpg)
+{
+	struct usb_function_instance *f = tpg->fi;
+	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
+
+	if (opts->tcm_register_callback)
+		return opts->tcm_register_callback(f);
+
+	return 0;
+}
+
+static void usbg_detach(struct usbg_tpg *tpg)
+{
+	struct usb_function_instance *f = tpg->fi;
+	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
+
+	if (opts->tcm_unregister_callback)
+		opts->tcm_unregister_callback(f);
+}
+
+static int tcm_set_name(struct usb_function_instance *f, const char *name)
+{
+	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
+
+	pr_debug("tcm: Activating %s\n", name);
+
+	mutex_lock(&opts->dep_lock);
+	opts->ready = true;
+	mutex_unlock(&opts->dep_lock);
+
+	return 0;
+}
+
+static struct usb_function_instance *tcm_alloc_inst(void)
+{
+	struct f_tcm_opts *opts;
+	int i;
+
+
+	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+	if (!opts)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&tpg_instances_lock);
+	for (i = 0; i < TPG_INSTANCES; ++i)
+		if (!tpg_instances[i].func_inst)
+			break;
+
+	if (i == TPG_INSTANCES) {
+		mutex_unlock(&tpg_instances_lock);
+		kfree(opts);
+		return ERR_PTR(-EBUSY);
+	}
+	tpg_instances[i].func_inst = &opts->func_inst;
+	mutex_unlock(&tpg_instances_lock);
+
+	mutex_init(&opts->dep_lock);
+	opts->func_inst.set_inst_name = tcm_set_name;
+	opts->func_inst.free_func_inst = tcm_free_inst;
+	opts->tcm_register_callback = tcm_register_callback;
+	opts->tcm_unregister_callback = tcm_unregister_callback;
+
+	config_group_init_type_name(&opts->func_inst.group, "",
+			&tcm_func_type);
+
+	return &opts->func_inst;
+}
+
+static void tcm_free(struct usb_function *f)
+{
+	struct f_uas *tcm = to_f_uas(f);
+
+	kfree(tcm);
+}
+
+static void tcm_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	usb_free_all_descriptors(f);
+}
+
+static struct usb_function *tcm_alloc(struct usb_function_instance *fi)
+{
+	struct f_uas *fu;
+	unsigned i;
+
+	mutex_lock(&tpg_instances_lock);
+	for (i = 0; i < TPG_INSTANCES; ++i)
+		if (tpg_instances[i].func_inst == fi)
+			break;
+	if (i == TPG_INSTANCES) {
+		mutex_unlock(&tpg_instances_lock);
+		return ERR_PTR(-ENODEV);
+	}
+
+	fu = kzalloc(sizeof(*fu), GFP_KERNEL);
+	if (!fu) {
+		mutex_unlock(&tpg_instances_lock);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	fu->function.name = "Target Function";
+	fu->function.bind = tcm_bind;
+	fu->function.unbind = tcm_unbind;
+	fu->function.set_alt = tcm_set_alt;
+	fu->function.get_alt = tcm_get_alt;
+	fu->function.setup = tcm_setup;
+	fu->function.disable = tcm_disable;
+	fu->function.free_func = tcm_free;
+	fu->tpg = tpg_instances[i].tpg;
+	mutex_unlock(&tpg_instances_lock);
+
+	return &fu->function;
+}
+
+DECLARE_USB_FUNCTION(tcm, tcm_alloc_inst, tcm_alloc);
+
+static int __init tcm_init(void)
+{
+	int ret;
+
+	ret = usb_function_register(&tcmusb_func);
+	if (ret)
+		return ret;
+
+	ret = target_register_template(&usbg_ops);
+	if (ret)
+		usb_function_unregister(&tcmusb_func);
+
+	return ret;
+}
+module_init(tcm_init);
+
+static void __exit tcm_exit(void)
+{
+	target_unregister_template(&usbg_ops);
+	usb_function_unregister(&tcmusb_func);
+}
+module_exit(tcm_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sebastian Andrzej Siewior");